Maximum physical performance tests appear to best reflect athletes’ training status and readiness to perform; however, it is unfeasible for practitioners to implement physical performance tests while trying to minimise the effects of fatigue during training. Subjective self-reported well-being measures have therefore been purported as a tool for monitoring athletes’ readiness to perform without exertion. The purpose of the current study was to establish the nature and strength of the relationship between changes in physical performance test scores and changes in well-being scores in student soccer players. For the purpose of this investigation, the physical performance test scores (jump height (JH), 10 m and 40 m sprint tests, 5-0-5 and YO-YO) and well-being scores (fatigue, energy, stress, motivation, soreness, sleep and total well-being score (TWS)) were collected for 48 male student soccer players at three time points (testing observation one: T1; testing observation two: T2; testing observation three: T3) over a period of two weeks in order to assess percentage change scores for physical performance test scores and well-being scores between T1 and T2, T2 and T3, and T1 and T3. Once percentage change scores (physical performance test scores and well-being scores) for each comparative pair of testing observations were calculated, Spearman’s rank order correlation coefficients (r) were calculated to evaluate the nature and strength of the relationships between changes in well-being scores and physical performance test scores. The principal findings of this study were that over two weeks of training, improved JH was associated with better motivation and worse fatigue, soreness and TWS. Faster 10 m and 40 m sprint times were associated with worse energy, stress, sleep and TWS. Faster 5-0-5 time was associated with worse fatigue, stress, sleep and TWS. Longer YO-YO distance was associated with worse motivation, stress, sleep and TWS. However, in many instances, correlations between physical performance test scores and well-being scores were small to trivial. Numerous contradicting correlations were also found across all comparative pairs of testing observations. The take-home message of this study is that subjective measures of well-being may not be purported as good measures for assessing athletes’ readiness to perform. Thus, physical performance tests are the ultimate indicator of athletes’ readiness to perform in this regard. Our findings suggest that during pre-season, worse well-being may be reported; however, athletes’ readiness to perform may not be negatively affected. Coaches and sport scientists should consider measuring both subjective self-reported measures of well-being and physical performance tests as these measures appear to be assessing two separate concepts. / Dissertation (MSc (Sport Science))--University of Pretoria, 2019. / Physiology / MSc (Sport Science) / Unrestricted

Master of Science / Department of Human Nutrition / Mark Haub / The purpose of this review is to examine the role of heart rate variability (HRV) as a predictor of athletic readiness and performance and assess whether nutrition strategies can be implemented to create favorable HRV indices with the goal of improving athletic readiness and performance. The balance between training and recovery is crucial for reaching an optimal adaptation and avoiding overtraining, allowing for improved readiness to train and compete. The measurement of HRV is non-invasive and is used primarily to quantify physical and mental stress in athletes by monitoring the effects of the autonomic nervous system on the heart. Current data suggests a relationship between resting parasympathetic tone, via time and frequency domains, and athletic performance. Parasympathetic modulated HRV indices have been associated with performance metrics such as peripheral work capacity, aerobic power, running and sprint performance, swimming performance, weight lifting performance, anaerobic capacity, strength, and enhanced mental focus/skill execution. The use of nutrition to help enhance sports performance is becoming more common. Evidence-based sports nutrition provides fuel for training/competition, assists in maximizing training adaptations, enhances recovery, improves mental focus, and aids in injury prevention and recovery. The use of nutrition strategies to influence HRV is novel and current evidence is scarce in regards to nutritional effects on HRV, specifically in athletes. Current research suggests that achieving energy balance and decreasing body fat in overweight/obese individuals has positive effects on the vagal component of HRV indices. Proper hydration, fruit and vegetable intake, a moderate carbohydrate diet, omega-3 fatty acid supplementation/intake also seem to have positive effects on HRV indices. Certain individual supplements have been studied in regards to HRV including casein hydrolysate, amaranth oil, and bovine colostrum. Caffeine seems to have the opposite effect on HRV indices, increasing sympathetic modulation while decreasing parasympathetic modulation. Much more research needs to be done in regard to potential nutritional influences on HRV so that sport dietitians feel confident in the methods currently used to assess athlete readiness and determining what types of nutrition strategies may be used to further improve the performance of an athlete.